Cryptoporus volvatus

Scientific name:   Cryptoporus volvatus (Peck) Shear
Derivation of name:   Cryptoporus means "with secret or
hidden pores;" volvatus means "provided with a volva."
Synonymy:   Polyporus volvatus Pk.
Common names:   Veiled polypore.
Phylum:   Basidiomycota
Order:   Polyporales
Family:   Polyporaceae
Occurrence on wood substrate: Saprobic; solitary or
grouped on the bark of stumps and standing dead conifers,
reported on living trees; May through August.  
Dimensions:  Cap 1.5-8.5 cm wide.  
Upper surface:  Fruit bodies (caps) are almost spherical to
hoof-shaped with the margin descending over the pores to form
a veil-like covering; whitish at first, becoming tan; smooth.       
Pore surface: White to brown; hidden by cap veil.
Edibility: Inedible.
Comments: An opening develops on the underside at maturity
to facilitate spore dispersal.  This is the only veiled polypore.
 
More information at MushroomExpert.com:


Figure 1. Cryptoporus volvatus on pine.
Photo © Gary Emberger.


Figure 2. Cryptoporus volvatus on conifer bark.
Photo © Larry Grand.

Figure 3. The small opening that develops on the underside.
Photo © Tom Volk.

Figure 4. Enlarging the opening reveals the pores.
Photo © Gary Emberger.

Figure 5. The brown pore surface, fully revealed by
removing the veil formed by the cap. Photo © Gary
Emberger.

Figure 6. A vertically sectioned specimen. The pore
through the veil is at the lower right and bark from the tree
is visible on the right side of the specimen. Brown spores
form a deposit pattern on the inside of the veil. The tubes,
up to 6 mm long, and the context are clearly visible in this
section. Photo © John Dawson.